OPTICAL-PHASE SHIFT OF POLYMER-DISPERSED LIQUID-CRYSTALS

We report a detailed study of the optical phase shift induced by a pol ymer-dispersed liquid crystal subjected to a low-frequency electric fi eld. A relationship between the optical phase shift and the droplet an d sample order parameters S(d) and S(f) is worked out in order to expl ain the experimental data obtained using an ellipsometric technique. T he measurements taken for several incidence angles are in very good ag reement with the expected behavior if an increase of the droplet order parameter is also considered when increasing the field. The method ap pears suitable to study reorientation phenomena in polymer-dispersed l iquid crystals overcoming the problems due to light scattering in thes e materials.